Buggy code:
@ Service public final class SearchServiceImpl implements SearchService { private static final Logger logger = LoggerFactory . getLogger ( SearchServiceImpl . class ) ; private final Map < String , Map < String , Set < SearchCriterionImpl > > > savedSearches = new ConcurrentSkipListMap < > ( ) ; @ Autowired ( required = true ) private SearchDao searchDao ; @ Override public void setSearchDao ( SearchDao searchDao ) { } @ Override @ PostConstruct public void initialise ( ) { } public SearchServiceImpl ( ) { } private void clearCache ( String owner ) { } private void clearCache ( String owner , String searchKey ) { } private boolean areSearchCriteriaCached ( String owner ) { } private boolean areSearchCriteriaCached ( String owner , String searchKey ) { } private Set < SearchCriterionImpl > getCriteriaFromCache ( String owner , String searchKey ) { } private Map < String , Set < SearchCriterionImpl > > getCriteriaFromCache ( String owner ) { } private void addCriteriaToCache ( String owner , String searchKey , String name , String value , Boolean isPrivate ) { } @ Override public Set < SearchCriterionImpl > get ( String owner , String searchKey ) { } @ Override public Map < String , Set < SearchCriterionImpl > > get ( String owner ) { } @ Override public Map < String , Map < String , Set < SearchCriterionImpl > > > get ( ) { } @ Override public boolean insert ( String owner , String searchKey , String name , String value , Boolean isPrivate ) { if ( ( owner == null ) || ( owner . isEmpty ( ) ) ) { if ( SearchServiceImpl . logger . isErrorEnabled ( ) ) SearchServiceImpl . logger . error ( "owner<seq2seq4repair_space>argument<seq2seq4repair_space>is<seq2seq4repair_space>invalid" ) ; throw new IllegalArgumentException ( "owner<seq2seq4repair_space>argument<seq2seq4repair_space>is<seq2seq4repair_space>invalid" ) ; } if ( ( searchKey == null ) || ( searchKey . isEmpty ( ) ) ) { if ( SearchServiceImpl . logger . isErrorEnabled ( ) ) SearchServiceImpl . logger . error ( "searchkey<seq2seq4repair_space>argument<seq2seq4repair_space>is<seq2seq4repair_space>invalid" ) ; throw new IllegalArgumentException ( "searchKey<seq2seq4repair_space>argument<seq2seq4repair_space>is<seq2seq4repair_space>invalid" ) ; } if ( ( name == null ) || ( name . isEmpty ( ) ) ) { if ( SearchServiceImpl . logger . isErrorEnabled ( ) ) SearchServiceImpl . logger . error ( "name<seq2seq4repair_space>argument<seq2seq4repair_space>is<seq2seq4repair_space>invalid" ) ; throw new IllegalArgumentException ( "name<seq2seq4repair_space>argument<seq2seq4repair_space>is<seq2seq4repair_space>invalid" ) ; } if ( ( value == null ) || ( value . isEmpty ( ) ) ) { if ( SearchServiceImpl . logger . isErrorEnabled ( ) ) SearchServiceImpl . logger . error ( "value<seq2seq4repair_space>argument<seq2seq4repair_space>is<seq2seq4repair_space>invalid" ) ; throw new IllegalArgumentException ( "value<seq2seq4repair_space>argument<seq2seq4repair_space>is<seq2seq4repair_space>invalid" ) ; } if ( SearchServiceImpl . logger . isDebugEnabled ( ) ) <START_BUG> SearchServiceImpl . logger . debug ( ( "Inserting<seq2seq4repair_space>the<seq2seq4repair_space>search<seq2seq4repair_space>with<seq2seq4repair_space>search<seq2seq4repair_space>ID" + searchKey ) ) ; <END_BUG> ReentrantLock lock = new ReentrantLock ( ) ; try { lock . lock ( ) ; addCriteriaToCache ( owner , searchKey , name , value , isPrivate ) ; return this . searchDao . insert ( owner , searchKey , name , value , isPrivate ) ; } finally { lock . unlock ( ) ; } } @ Override public boolean delete ( String owner , String searchKey ) { } @ Override public boolean delete ( String owner ) { } }

Fix:
SearchServiceImpl . logger . debug ( ( "Inserting<seq2seq4repair_space>the<seq2seq4repair_space>search<seq2seq4repair_space>with<seq2seq4repair_space>search<seq2seq4repair_space>ID:<seq2seq4repair_space>" + searchKey ) ) ;